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s Epp-jeds\5M\9+i'-p inch by 2-inch brass rings lining a split-spoon sampler. The sampler was driven 18 inches into undisturbed soil before being retrieved and split open to remove the rings. The ends of the lowermost ring were covered with teflon sheets before being capped,sealed with duct p, tape, labeled, and stored in an ice chest for possible laboratory analysis. Soil from the other rings was screened by sight,odor,and with a photoionisation detector Organic Vapor Analyzer for hydrocarbons. Soil samples and cuttings from the boring were logged and ' geologically described by a geologist on site. Samples from the boring show that the soil beneath the site consists primarily of brown clayey to sandy silt, with some sand intervals ! encountered (Appendix A- Boring Log). 2.2 Monitoring Well Construction E-� Ground-water was noted during drilling at approximately 92 feet. The well was drilled to 103 feet,screened with 0.02-inch slotted PVC casing from 103 to 83 feet and sand-packed with#2/12 Monterey sand from 103 feet to 73 feet. A 2-foot layer of bentonite pellets was added from 73 to 71 feet,and neat cement grout was tremied around the blank PVC casing as a seal from 71 feet to the surface. A locking well cap and traffic-proof well box were installed at the surface. 23 Ground-Water Gradient The ground-water gradient was determined using UST-1 and three other monitoring wells (SI-1,SI-2,and SI-3)on site installed as part of another investigation approximately 500 feet from the fueling area (Figure 1). The four wells encountered ground water at approximately 83 to 92 feet during drilling. Static ground-water levels in the wens were measured at 84• to 85 feet on September 25, 1990, except in Well SI-3, where a ground- water level was not obtained because of excessive silt in the well casing. Figure 1 shows Y.. the ground-water gradient is approximately .00063 ft/ft or 3.3 ft/mile, to the west. 2A Soil and Ground-Water Analytical Results r. - — --- --- -Soil containing hydrocarbons was encountered during drilling from_10 to 80 feet based upon field observation and on-site organic vapor analysis. Soil samples from 50, 70, and 85 feet T ;" 2